This returns a map of the percentiles you probably care about. The keys are the
percentiles (doubles between 0 and 1 inclusive) and the values are the maximum
time taken for that percentile. In this example:

75% of images were processed in 232.00 milliseconds or less.

95% of images were processed in 240.23 milliseconds or less.

... etc.

If you want a different set of percentiles just pass them as a sequence: